This document relates to semiconductor structures, devices and fabrication techniques.
Semiconductor structures may include defects due to various factors, such as mismatch in properties of two different materials that are adjacent to and interface with each other. Common defects found in strained semiconductor film stacks due to differences in crystalline structures in the film stacks include threading dislocations (TDs) that often appear on surfaces of the strained semiconductor film stacks and propagate through film stacks in GaN and other semiconductor materials.
Threading dislocations and other defects in semiconductor structures can adversely affect the device performances and reliability. Various efforts have been made in reducing the threading dislocation density in semiconductor structures.